Correspondent photo / Karla Dines Donna Campbell of Warren attended a talk Wednesday evening at the Warren-Trumbull County Public Library on Ohio fossils because of her interest in dinosaurs. Campbell said she 3-D prints dinosaurs as a side hobby and is shown holding one of them. The talk was presented by Carrie Schweitzer, a professor in the Department of Earth Sciences at Kent State University.

WARREN — One might stumble upon a strange, patterned rock in an Ohio creek after heavy rain and wonder whether it is a fossil and, if so, what kind.

A child visiting the Cleveland Museum of Natural History might wonder if the dinosaur remains on display once lived in the area.

Just how abundant fossils are in Ohio, and what types of ancient animal and plant life inhabited Ohio were the topics of a presentation by Carrie Schweitzer, a professor in the Department of Earth Sciences at Kent State University, on Wednesday evening at the Warren-Trumbull County Public Library.

Although Schweitzer’s main research interests are crustacean fossils — shrimp, lobsters and crabs — her talk covered fossils from ancient marine life and plant fossils to Ice Age mammals.

“Most of the fossils you would find in Ohio are 488-359 million years old,” Schweitzer said.

Glaciers had little impact on fossils in the area. Mostly, fossils are found in areas where bedrock is exposed. Although sometimes Ice Age mammals are found in glacial deposits.

The most common type of fossil found in Ohio is Brachiopods.

“They are an interesting animal because superficially they look a lot like clams. Like clams, they have two shells. If you peel open a Brachiopod, and you can see the guts sticking out, it is totally different than what is inside a clam,” Schweitzer said.

They were probably occupying the same niche in the environment as clams and were very abundant during the Paleozoic period. The shells of Brachiopods are not mirror images like clams are. These are very abundant in the Cincinnati area, where rocks are full of them.

The second most common fossil in Ohio are the Bryozoans. These can still be found in the oceans and have a branching, coral-like appearance.

The next most likely fossil to be found in Ohio are corals. Horn corals are very common. They are common in Cincinnati, Kelleys Island, Put-in-Bay and Marblehead. Snails are also common to these areas.

Ice Age mammals, mastodons and mammoths also lived in Ohio, as did other vertebrates, such as the Dunkleosteus — Ohio’s state fossil fish.

Donna Campbell of Warren attended Schweitzer’s talk because of her interest in dinosaurs.

“We print 3-D dinosaurs as a side hobby. I thought this talk would be interesting,” Campbell said.

Ohio’s most famous fossil parks are Sylvania Fossil Park, Paulding County Community Fossil Garden, Hueston Woods State Park, Trammel Fossil Park, Oakes Quarry Park, Caesar Creek Spillway, Cowan Lake State Park and East Fork State Park Fossil Park.

“For just finding tons of fossils — Caesar Creek. Everyone can find fossils. You can’t not find fossils there. Because these rocks are just all fossils. You are allowed to take any fossils smaller than your hand,” Schweitzer said.

Schweitzer said that a common question she gets is if trilobites, which are extinct marine arthropods, are found in Ohio. They are, but it is rare to find complete specimens, and they are not common in northeast Ohio.

Schweitzer explained that while dinosaur bones have not been found in Ohio, they have been found in New Jersey, so it is assumed dinosaurs also lived in this area.